Aids (sic) is a fatal disease caused by human innumodeficiency virus (HIV). During the life cycle of HIV, its reverse transcriptase is an essential enzyme required for its replication. Therefore, it is an excellent target for anti-HIV therapeutics; and extensive effort is focused on searching for its inhibitors. This is hindered, because HIV is dangerous to handle and expensive to produce. This proposed research is to construct a recombinant Moloney murine leukemia virus carrying HIV reverse transcriptase. This novel virus will have all the advantages of an ecotropic murine retrovirus including biosafety, high yield and low cost of production. Meanwhile, it will carry authentic HIV reverse transcriptase for the development of authentic, safe and simple assays. The recombinant virus can be constructed by splicing the DNA encoding HIV reverse transcriptase to the Moloney leukemia virus vector. Following transfection with the DNMA construct, transmission recombinant viruses may be isolated. This novel approach could speed up the anti-HIV drug screening program by supplying safe biological reagents with greatly reduced cost. Furthermore, by combining with other assay systems and screening strategies that proposed phase II research intends to accomplish, there is a reasonably (sic) good chance that effective and safe therapeutics for AIDS can be found.